Chapter 11 - Counting Methods and Probability Theory - 11.1 The Fundamental Counting Principle - Exercise Set 11.1 - Page 693: 7

$40$

The number of ways in which a series of successive things can occur is found by multiplying the number of ways in which each thing can occur. ---------- 1. The type of drink can be chosen in $2$ ways. 2. The size of the drink can be chosen in $4$ ways. 3. The flavor can be chosen in 5 ways. Applying the Principle, the total number of drinks is $2\times 4\times 5=40$